This invention pertains generally to Nut Looseness or Torque Indicators. More particularly, it deals with a unique combination looseness indicator and dust cap. Nut looseness or torque indicators are installed on the wheels of many military and commercial vehicles as they provide an easy visual means for confirming or detecting the looseness of wheel lug nuts. When combined with dust caps, they also help to protect the lug nut assembly from dust and other road hazards. FIG. 1 shows the current state of the art of nut torque indicators, while FIG. 2 shows a prior art dust cap or cover for a lug nut. The nut torque indicator 1 of FIG. 1 is pressed onto a hex nut 2. A knurled surface 3 of the nut torque indicator 1 interfaces with the hex flats 4 of the hex nut 2. As the hex nut 2 rotates relative to the bolt 5, the nut torque indicator 1 rotates with it, made visible to an operator by the pointer 6. This allows a user to know if a bolted connection is losing torque. FIG. 2 shows a nut cover 7 that is used to protect the exposed external threads 8 of a bolt 5. The nut cover 7 is pressed onto the external threads 8 of the bolt 5 and are secured by tabs 9 on the inside diameter of the nut cover 7. Further examples of prior art including and combining the functions of nut torque indicators and dust covers can be found in U.S. Pat. Nos. 6,398,312; 6,561,124; and 6,595,597 by Marczynski et al.
Still, all of these prior art approaches to nut torque/looseness indicators have disadvantages. First, prior art nut torque indicators are difficult to remove from the nut once assembled. Second, many nut torque indicators do not provide any protections for the bolt threads. Third, torque indicator pointers are too long and can be damaged by rocks or road debris. Also, interference can occur with other components on the assembly that are in close proximity. However, the instant invention resolves and avoids these difficulties by teaching a design where the fastening of the nut torque indicator cover to the nut/bolt assembly is achieved primarily by pressing onto exposed threads of the bolt and secondarily to the hex portion of the nut. A snap fit design is incorporated into the nut torque indicator cover such that it consists of multiple parts that can rotate relative to each other. The cover piece fastens securely to the external threads of the bolt providing protection to the threads, while the indicator piece, interacting with the hex flats of the nut, indicates the nut circumferential position, allowing an indication of any torque loss.
The foregoing features and others of the inventive concept, as more fully described below, provide numerous advantages over the systems of prior art. To begin with, the cover piece and the indicator piece are joined by a unique snap fit design such that the two parts can rotate relative to each other. In addition, assembly and disassembly of the nut torque indicator cover is improved. The cover piece of the nut torque indicator cover fastens to the external threads of the bolt and installs simply by pressing onto the external threads. Disassembly can be accomplished by unscrewing the cover piece from the stud threads. Further, the indicator piece utilizes a smaller pointer to reduce or eliminate damage and/or interference from impacts and other hazardous environments. This also allows allows adjacent nuts to be in closer proximity than previously possible. The numerous other advantages of our invention will become more apparent in view of the more detailed description and claims that follow.